Automatic grab



H. REICHMANN AUTOMATIC GRAB July 1, 193m Fiied March 9, 1923 2sheets-sheet 1 July l, 1930. H. REI-CHMANN AUTOMATIC GRAB Filed March 9,1928 2 Sheets-Sheet 2 Patented July 1,1930r i.

'ITED STATES Hammer: mucmmniv,

F DUISBURG, GERMANY AUTOMATIC G Application led. March 9, 1928,

This invention relates to an automatic grab which is provided with aplurality of grippers members or its free adjustment is impeded orlimited by abutment members in the closed position, as well as in theopen one, of the grippers or jaws.

Now, in order to enable the individual grippers or jaws to accommodatethemselves automatically in every position to any unforeseen resistanceand to compensate this latter by acting upon the other grippers or jaws,the present improved grab is so designed that the pivotal connections ofthe grippers or jaws form, in the open, as well as in the closedposition of the latter, a self-adjusting multijaw joint capable ofyielding in all directions in the case of resistance arising.

in order to render it possible to increase the yieldability and theadjustability of the gripper or jaw ends when-very bulky parts are to beseized and lifted, there is enough play left in every jaw joint topermit every one of the jaws and unconstrained adjustment also outsideof its normal middle plane.. Furthermore, in order to attain forcefulentering of the grippers or jaws into the material to be seized andlifted, their middle pivot points are located about equally remote fromthe end of the same and from the upper pivot points, and the shape ofthe grippers or jaws is correspondingly and suitably chosen', as moreful-ly described hereinafter.

The invention isillustrated diagrammatically and by way of example inthe accompanying drawing, in which Fig. 1 is a side grab designedaccording to this inview of a 45 vention, there being, however, shown 1nthis iron, ore an kept Serial No.

d plane lll- IH of Fig.

guide g away 260,269, and in Germany March 11, 1927.

figure only those jaws which are located in the plane of the paperof-the drawing, and these jaws are shown in two positions, viz.

in full lines in closed position and'in dotted lines in the open one;Fig. 2 is a horizontal 5@ section in the plane --U of Fig. l; Fig.

3 is a section through the lower sleeve in the l; Fig. 4: shows one ofthe grippers or jaws and its operating rod toether with halves of theupper and of the 5;; lower sleeve, this gure being drawn to an enlargedscale; Fig. 5 is an outer or edge view ofthe operating rod or, moreprecisely, of several connected operating rods relating to one gripperor jaw, the scale being a@ the same as that of Fig. 4; and Fig. 6 is anouter view of the gripper or jaw shown in Fig. Li.

On the drawing, B denotes the lower sleeve, and .C are the curvedgrippers or jaws (for as instance, eight, as in the example shown inFig. 2) which are jointed to the sleeve B by ivots l. rlhe grippers orjaws are connected by bolts 3 with the lower ends of rods D, the latterbeing hinged at their upper ends to the upper sleeve A by means of bolts2 upon which these members C and D have some lateral play. A rope L, theclosing rope, is guided over pulleys 01l and b mounted respectively onthe sleeves A and B, one end of said rope being fastened in any suitablemanner, so that when the other end of the rope is subjec'ted to a pullthe two sleevesare moved toward one another, with the result that thegrab is closed. When said end of the rope 5U L is again released, thelower sleeve moves from the upper one by its own weight and the grabjaws or arms C are opened. rli`he upper sleeve is suspended from a ropeE, or from two ropes E, as in the example shown in the drawing; in theillustrated example the two lropes E are not attached directly to thesleeve a, but by means of an upwardly directed flat bar F fixed to saidsleeve, and horizontal member G which a; is connected with 9@ j dle saidbar by a pivot G. The lower sleeve is preferably made as wide aspossible and the pivots 1 of the grippers or jaws are located at thecircumference of this sleeve so that they are as remote as possible fromthe midaxis of the gripper or jaw. Owing to th1s arrangement the lowersleeve'can assume anoblique position relativel to the upper sleeve, thewhole, including the joints 1, 2 and 3, thus forming an automaticallyadjustable multi-jaw support which is yielding in all directionsand thegripping jaws of which accommodate themselves automatically to any bulkymaterial, and to any un` equal resistance developed thereby.

If, therefore, jaws encounters a particularly strong resistance owing tothe presence of some bulky parts to be seized and lifted, thelowersleeve flange is free to assumea suitably oblique positionrelatively to the position of the upper sleeve and re-adjustsautomatically all other grippers or jaws Vso that their gripping actionlis correspondingly increased. This yielda'bility of the grippers or jawsto resistances arising atfdili'erent relativelydifferent strength isstill further materially increased by the `fact that the lower sleeve ismade as wide as possible and the pivots 1 are arranged, as far aspossible, at the Vcircumference of said sleeve because in such a casethe individual grippers or jaws are able to exert a great turning momentupon the lower sleeve. In addition the arrangement providesl a largervnumber of grippers or jaws, that is, a better distribution of theforces, and this entails the further advantage that if, for' instance,such parts as wooden beams, girders, or the like must be seized andlifted, oppositely located grippers or jaws maybe detached from the grabso that the respective parts are .seized only at their sides.

he readjustment of the grippers or jaws is eii'ected in the usual mannerby lifting or lowering, as the case may be, the sleeve B relatively tothe sleeve A.

In order to provide for a very great flexibility and adaptability of thegrippers or jaws, all movable members of the same have a predeterminedplay in their bearings of such an amount that they can be shiftedlaterally to a certain extent. Thus, for instance, the rods D may beshifted laterally on the pivots 2 by as much as the distance av in Fig.5 and on the pivots 1 and 3 by as much as the distance y in Fig. 5 and zin Fig. 6. All gripper or jaw joints form, therefore, in spite of theirbelng positive-ly connected with one another. and by reason of the playmentioned, a perfectly loose, self-adjusting joint connection able toaccommodateitself in every diany one of the grippers or` places and ofapart by spacin members f or proper equivalents. The mem ers g are arraned edgewise, as shown, and consist of flexible steel. The

be chosen ac- 'struction of the rods D, and in spite of their lowweight, they are able to withstand all strains which are directedtowards the middle axis'of the grab or by wh members composing themrespectively, are subjected to bending stresses. If, h when particularlyresistant elements are to be seized and lifted, the laterally directedforces are so great that the dead play existing is not sulicient toeffect the equalization, then the rods D, or the members g respectively,and with them the grippers or jaws, can singly give way laterally to acertain extent. The transmission of the forces is facilitated by thefact that the ribs c (Figs. 4 and 5) of the grippers or jaws extendbetween the memers g in the manner shown in these figures. When the jawshave been opened and the load has 'been discharged, they quickly re#turn to their former position under the elas-v ich said rods, or the.

owever, v

Vide for an effective transmission of the lateral forces in this case,the ribs c extend between the members g, as already described.

The described construction of the individual gripper or jaw jointsincreases considerably the ability of the jaws to accommodate themselvesto existing conditions, and adds to the indifference of the grippers orjaws to bulky parts whereby the life of the grab is materiallyincreased. -f j In order to prevent the jaws from jumping over the partsto be seized and lifted, or, in other words, in order to force them intothe material and cause them to rake the respective parts together, theposition of the pivots 1 and 3 of the jaws is so chosen that the mid dlepivot 3 of each jaw is equally spaced from the tip z. and from th jaw.It is possible with this novel arrange ment to have the pivots 3 locatedonly slight ly above that horizontal plane in which the jaw tips arelocated when the grab is closed. he penetration of the grippers or jawsinto the" material to be seized and. lifted is e upper pivot 1 of .the

promoted also by .the fact that the operating material when the tips 71.are

an Iupper sleeve,

said sleeves whereby the latter are capable of tilting and otherwisemoving relatively to each other, gripping jaws for grabbing the materialto be raised, flexible pivotal connections between said jaws and saidlower between said rods and said pivotal connections between said rodsand sald upper sleeve, and jaws, the mobility and flexibility of saidconnections permitcomprising, in combination,

matically,

tin universal movements in the gripping en s of said jaws whereb thelatter automatically accommodate t emselves to any unequal resistancesdeveloped by the material l being gripped.

2 automatic grab for bulky materials, an upper sleeve,

a lower sleeve, a mobile connection between said sleeves whereby thelatter are capable of tilting and otherwise moving relatively to eachother, gripping jaws for grabbing the material to be raised, loosepivotal connections between said jaws and said lower sleeve,` foperating bars for said jaws, and loose pivotal connections between saidbars and said upper sleeve .and jaws respectively, the mobility andlooseness of said connections permittmg universal movements of thegripping ends of said jaws whereby the latter automatically accommodatethemselves to any unequal resistances developed by the material beinggripped.

An automatic grab for bulky materials, comprising, in combination, anupper sleeve, a lower sleeve, a mobile connection between said sleeveswhereby the latter are capable of tilting and otherwise movingrelatively to each other, gripping jaws for grabbing the material to beraised, pivotal connections between said jaws and said lower sleeve onwhich said jaws have predetermined lateral play to permit relativelateral movements of the jaws out of their planes of normal pivotalmovement, operating rods for said jaws, and pivotal connections betweensaid rods and said upper sleeve, and between said rods and said jaws, onwhich said operating rods have predetermined lateral play to permitrelative lateral movements of the operating rods out of their planes ofnormal pivotal movement, the mobility of said connections and the playtherein permitting universal movements of the gripping ends of said jawswhereby the latter automatically accommodate them.- selves to anyunequal resistances developed by the material being gripped.

4. Aan automatic grab for bulky materials,

comprising, in combination, an upper sleeve, a lower sleeve, a flexibleconnection between said sleeves, gripping jaws hinged to said lowersleeve, and Hexible operating rods hinged to said jaws and to said uppersleeve and capable'of yielding laterally, the hinge connections beingloose and with the flexibility of the connection between the sleeves,and the flexibility of the rods permitting the gripping jaws to adjustthemselves autoin the open position and in the operating rods for closedosition, to an unequal resistances developed) by the material beinggripped.

5. An automatic grab comprising, in eombinatioman upper sleeve, a lowersleeve, gripping jaws loosely hinged to said lower sleeve, operatingrods loosely hinged A'to said jawsand to said upper sleeve and eachconsisting of a plurality of flexible flat steel members arrangededgewise and spacing members arranged between said rod members forfixing said members in spaced relation, the loosenessv of the hingeconnections andthe flexibility o f the operating rodsy permittingfthegripping jaws to adjust themselves automatically, in the open positionand in the closed position, to any unequal resistances developed by thematerial being gripped.

6. An automatic grab for bulky materials, comprising, in combination, anupper sleeve, a lower sleeve, gripping jaws loosely hinged to said lowersleeve, hinged to said jaws and to said upper sleeve, and eachconsisting of at least two spaced parallel members, and a rib on eachjaw ea:- tending into the .space between the parallel membersconstituting the co-operating operating rod, the looseness of the hingeconnections permitting the gripping jaws to adjust themselvesautomatically, in the open position and in the closed position, to anyunequal resistances developed by the material being gripped.

7. An automatic grab for bulky materials, comprising, in combination, anupper sleeve, a lower sleeve, gripping jaws loosely hinged to said lowersleeve, and operating rods loose-- ly hinged to said jaws and to saidupper sleeve, the hinge connection of each jaw with its operating rodtween the gripping point of each jaw and its hinged connection with thelower sleeve.

8. An automatic grabfor bulky materials, comprising, in combination, anupper sleeve, a lower sleeve, gripping jaws loosely hinged to said lowersleeve, and operating rods loosely hinged to said jaws and to said uppersleeve, the hinge connection of each jaw with its operating rod beinglocated slightly above the horizontal plane in which the gripping pointsof the jaws are located when the grab is closed.

9. An automatic grab for bulky materials, comprising, in combination, anupper sleeve, a lower sleeve, gripping jaws loosely hinged to said lowersleeve, and operating rods loosely hinged to said jaws and to said uppersleeve, the operating face ofeach jaw being so shaped as to extend in apractically straight line from the gripping end towards the hingeconnection with the operating rod and along a curved line toward thehinge connection with the lower sleeve.

l0. An automatic grab for bulky materials, comprising, in combination,an upper sleeve,

for bulky materials,

operating rods loosely being located midway bea lower sleeve, grippingjaws loosely pivoted to the lower sleeve2 and operating rods looselypivoted to saidv ]aws and to said upper sleeve, the vertical distance,in the closed position of the jaws between the grip 111g oints of theJaws and the horizontal p ane 1n which the pivotal connections of theoperating rods and the jaws are located being less than the verticaldistance between said horizontal plane andthe horizontal plane in whichthe pivotal connections of said jaws with said lower sleeve are located.

In testimony whereof I have aixed my signature. y

` HEINRICH REICHMLANN.

